TITLE:
Fate of Particulate Matter from Cruise-Ship Emissions in Glacier Bay during the 2008 Tourist Season
AUTHORS:
Michael Pirhalla, Scott Gende, Nicole Mölders
KEYWORDS:
Cruise-Ship Emissions, Temperature Inversions, Particulate Matter, Glacier Bay National Park, Pristine Air, WRF/Chem
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.12,
September
24,
2014
ABSTRACT: Simulations
from the Weather Research and Forecasting Model, inline coupled with chemistry,
were used to examine the fate of particulate matter with diameter of 10 μm or
less (PM10) in Glacier Bay, Alaska during the 2008 tourist season.
The simulations demonstrated that mesoscale and synoptic scale weather systems
affect the residence time of PM10, the magnitude of concentrations,
and its transport in and out of Glacier Bay. Strong inversions exceeding 2 K
(100 m)-1 cause notable trapping of pollutants from cruise-ship
emissions, increasing PM10 concentrations up to 43% compared to days
with cruise-ship visits without the presence of an inversion. Inversions
occurred locally in Glacier Bay on 42% of the 124-day tourist season with an
average lifetime of 9 h. Pollutants occasionally originated from outside the
National Park when southerly winds advected pollutants from ship traffic in Icy
Strait. Occasionally, orographically forced lifting over the Fairweather
Mountains transported pollutants from the Gulf of Alaska into Glacier Bay.
While hourly (daily) PM10 concentrations reached ~44 μg·m-3 (22 μg·m-3) in some areas of Glacier Bay, overall seasonal average
PM10 concentrations were below 2 μg·m-3. Despite up to
two cruise-ship visits per day, Glacier Bay still has pristine air quality.
Surface and upper air meteorological state variables were evaluated through an
extensive network of surface and radiosonde observations, which demonstrated
that the model was able to capture the meteorological conditions well.